Travelling grate machines

ABSTRACT

Apparatus for the gaseous treatment of solid materials comprising a plurality of pallets each having a base in the form of a grate and which are adapted to be moved in end-to-end abutting relationship through a treatment zone where a gaseous medium is passed through the material on the pallets from static wind boxes located below the pallets, characterized by the provision of dead plates extending over the width of the apparatus at the positions where the pallets enter and leave the treatment zone and by the provision of wear strips extending transversely of each pallet at the leading and trailing ends thereof and depending from the underside of the pallet to make contact with the dead plates as they pass thereover, said wear strips being of a softer material than the material of the dead plates, whereby the wear strips are worn away to accommodate for distortion of the pallets while maintaining a proper seal with respect to the dead plates.

Unite Burgess States Patent 1 TRAVELLING GRATE MACHINES [75] Inventor:Charles David Burgess, Cheshire,

England [73] Assignee: Simon-Carves Limited, Cheshire,

England [22] Filed: Aug. 27, 1971 [21] Appl. No.: 175,438

Primary ExaminerGerald A. Dost Attorney-James E. Nolan 1 March 6, 1973 57 ABSTRACT Apparatus for the gaseous treatment of solid materialscomprising a plurality of pallets each having a base in the form of agrate and which are adapted to be moved in end-to-end abuttingrelationship through a treatment zone where a gaseous medium is passedthrough the material on the pallets from static wind boxes located belowthe pallets, characterized by the provision of dead plates extendingover the width of the apparatus at the positions where the pallets enterand leave the treatment zone and by the provision of wear stripsextending transversely of each pallet at the leading and trailing endsthereof and depending from the underside of the pallet to make contactwith the dead plates as they pass thereover, said wear strips being of asofter material than the material of the dead plates, whereby the wearstrips are worn away to accommodate for distortion of the pallets whilemaintaining a proper seal with respect to the dead plates.

5 Claims, 3 Drawing Figures PAIE NTED MAR 61973 SHEET 1 OF 2 InVQfl/O/LChara: D/wlo EUECESS' Y GJJOYM SI TRAVELLING GRATE MACHINES Thisinvention concerns apparatus for the gaseous treatment of solidmaterials particularly, though not exclusively, apparatus for theagglomeration of ores and minerals, and being of the kind (hereinaftertermed of the kind referred to) wherein a plurality of pallets eachhaving a base in the form of a grate are adapted to be moved inend-to-end abutting relationship through a treatment zone where agaseous medium is passed through the material on the pallets by means ofstatic windboxes.

For efficient operation and to prevent the escape of dust and noxiousgases it is desirable to form a seal at the points of contact betweenthe pallets and the windboxes.

A variety of means have been proposed for effecting a seal between thesides of the pallets and the windboxes.

A further major potential source of leakage exists at the ends of thetreatment zone of the apparatus. In these regions it is customary toprovide so-called dead plates across the width of the machine, which areadjustable for height so that the under-surfaces of pallet cross-memberssupporting the grate pass over the dead plates sufficiently closely toform an adequate seal. Variations are known for the design of the deadplates including the use of beds of granular material which aremaintained at the appropriate level by the scraping action of the palletcross-members, and the use of springsupported dead plates which areurged upwardly against said cross-members.

It has been found that conventional dead plates as described above havea serious disadvantage in that the pallets may become distorted due tothe repeated heating and cooling to which they are subjected. Suchdistortion is commonly in the form of a downward bowing of the pallet.It will be apparent that the dead plates must then be modified toaccommodate the pallet having maximum distortion with the result thatother pallets which are not distorted to the same degree do not form anadequate seal with the dead plates.

It is an object of the present invention to provide improved sealingmeans at the ends of a treatment zone of apparatus of the kind referredto, and which overcome, at least to some extent the disadvantageaforesaid.

According to the present invention apparatus for the gaseous treatmentof solid materials comprising a plurality of pallets each having a basein the form of a grate which are adapted to be moved in end-to-endabutting relationship through a treatment zone where a gaseous medium ispassed through the material on the pallets by means of static wind boxesis characterized by the provision of dead plates extending over thewidth of the apparatus at the positions where the pallets enter andleave the treatment zone and by the provision of wear strips extendingtransversely of each pallet at the leading and trailing ends thereof anddepending from the underside of the pallet to make contact with the deadplates as they pass thereover, said wear strips being of a softermaterial than the material of the dead plates, whereby the wear stripsare worn away to accommodate for distortion of the pallets whilstmaintaining a proper seal with respect to the dead plates. The inventionwill be further apparent from the following description with referenceto the several figures of the accompanying drawings, which show, by wayof example only, one form of apparatus embodying the invention.

Of the drawings:

FIG. 1 shows a general arrangement drawing the apparatus;

FIG. 2 shows a cross-section of the apparatus on the line IlII of FIG. 1on an enlarged scale; and

FIG. 3 shows a cross-section of part of the apparatus on the lineIII-III of FIG. 2.

Referring firstly to FIG. 1 it will be seen that the apparatus comprisesa plurality of pallets 10 which are adapted to be moved continuously onrails 11 around an endless path having upper and lower runs. The pallets10 are in endto-end abutting relationship as they move along the upperrun through a treatment zone defined above windboxes 12 for the supplyof treatment gas disposed beneath the run.

Turning now to FIG. 2 it will be seen that each pallet has a base in theform of a grate 10a supported by transversely extending cross members10b. The number of cross members 10b is not critical so long as there isone such member located beneath the grate 10a adjacent both the leadingand trailing ends of each pallet 10. The pallets are equipped withwheels 13 which engage the rails 11 to enable the pallets to beprogressed around the apparatus. Sliding sealing means generallyindicated at 15 are provided between the sides of the pallets and thesides of the windboxes 12.

In accordance with the invention dead plates 16 are provided adjacentthe entry to and exit from the treatment zone and extend transversely ina horizontal plane between the rails 11 at these positions. The deadplates 16 extend longitudinally so as to overlap the extreme ends of thewindboxes 12 as clearly shown in the drawings. As can be seen from FIGS.1 and 3 each of the dead plates 16 has end portions of ramp-like formwhich incline downwardly from a central portion of maximum height. Theleading and trailing cross members 10b on each pallet 10 are providedwith slots 17 in their under-surfaces which locate wear strips 18 whichdepend therefrom and which are adapted to abut the dead plates 16 asthey pass thereover.

The wear strips 18 are formed from a material, such as a bronze which issofter than the material from which the dead plates 16 are formed. Thearrangement is such that as the pallets enter and leave the treatmentzone above the windboxes 12, the strips 18 slidably contact the plates16 forming a seal preventing escape of gases at these regions. Inoperation, as any pallet 10 becomes distorted, the wear strips 18 becomeworn by engagement with the plates 16 to accommodate such distortion. Itfollows that the strips 18 on each pallet are worn by different extentsdepending upon the degree of distortion experienced by each pallet andthat adequate seals are maintained for each pallet.

It will be understood that the wear strips 18 canbe made of sufficientdepth to accommodate considerable distortion of any pallet frame beforeother remedial action need be taken.

It will be appreciated that it is not intended to limit the invention tothe above example only, many variations, such as might readily occur toone skilled in the art, being possible without departing from the scopethereof.

What is claimed is:

1. Apparatus for the gaseous treatment of solid materials comprising aplurality of pallets each having a base in the form of a grate which areadapted to be moved in end-to-end abutting relationship through atreatment zone where a gaseous medium is passed through the material onthe pallets by means of static wind boxes, characterized by theprovision of dead plates extending over the width of the apparatus atthe positions where the pallets enter and leave the treatment zone andby the provision of wear strips extending transversely of each pallet atthe leading and trailing ends thereof and depending from the undersideof the pallet to make contact with the dead plates as they passthereover, said wear strips being of a softer material than the materialof the dead plates, whereby the wear strips are worn away to accommodatefor distortion of the pallets whilst maintaining a proper seal withrespect to the dead plates.

2. Apparatus according to claim 1, wherein said wear strips are locatedin slots on the under-surfaces of cross members which support the gratesof the pallets.

3. Apparatus according to claim 1, wherein the dead plates extendlongitudinally so as to overlap the extreme ends of the wind boxes.

4. Apparatus according to claim 2, wherein the dead plates extendlongitudinally so as to overlap the extreme ends of the wind boxes.

5. Apparatus according to claim 1, wherein the ends of each dead plateare defined by ramp portions which incline downwardly from a centralportion of maximum height.

1. Apparatus for the gaseous treatment of soLid materials comprising aplurality of pallets each having a base in the form of a grate which areadapted to be moved in end-to-end abutting relationship through atreatment zone where a gaseous medium is passed through the material onthe pallets by means of static wind boxes, characterized by theprovision of dead plates extending over the width of the apparatus atthe positions where the pallets enter and leave the treatment zone andby the provision of wear strips extending transversely of each pallet atthe leading and trailing ends thereof and depending from the undersideof the pallet to make contact with the dead plates as they passthereover, said wear strips being of a softer material than the materialof the dead plates, whereby the wear strips are worn away to accommodatefor distortion of the pallets whilst maintaining a proper seal withrespect to the dead plates.
 1. Apparatus for the gaseous treatment ofsoLid materials comprising a plurality of pallets each having a base inthe form of a grate which are adapted to be moved in end-to-end abuttingrelationship through a treatment zone where a gaseous medium is passedthrough the material on the pallets by means of static wind boxes,characterized by the provision of dead plates extending over the widthof the apparatus at the positions where the pallets enter and leave thetreatment zone and by the provision of wear strips extendingtransversely of each pallet at the leading and trailing ends thereof anddepending from the underside of the pallet to make contact with the deadplates as they pass thereover, said wear strips being of a softermaterial than the material of the dead plates, whereby the wear stripsare worn away to accommodate for distortion of the pallets whilstmaintaining a proper seal with respect to the dead plates.
 2. Apparatusaccording to claim 1, wherein said wear strips are located in slots onthe under-surfaces of cross members which support the grates of thepallets.
 3. Apparatus according to claim 1, wherein the dead platesextend longitudinally so as to overlap the extreme ends of the windboxes.
 4. Apparatus according to claim 2, wherein the dead plates extendlongitudinally so as to overlap the extreme ends of the wind boxes.